Fix make distcheck.

Makefile.am

 ACLOCAL_AMFLAGS = -I m4 -I ${VARNISHAPI_DATAROOTDIR}/aclocal
 
-SUBDIRS = src
+SUBDIRS = src src/tests/bench
 
 DISTCHECK_CONFIGURE_FLAGS = \
 	VMOD_DIR='$${libdir}/varnish/vmods'

src/tests/bench/Makefile.am

@@ -8,12 +8,12 @@ bin_PROGRAMS = bench bench_qp bench_ph
 
 bench_SOURCES = bench.c
 
-bench_LDADD = $(top_srcdir)/src/.libs/patricia.o
+bench_LDADD = $(top_builddir)/src/.libs/patricia.o
 
 bench_qp_SOURCES = bench_qp.c
 
-bench_qp_LDADD = $(top_srcdir)/src/.libs/qp.o
+bench_qp_LDADD = $(top_builddir)/src/.libs/qp.o
 
 bench_ph_SOURCES = bench_ph.c
 
-bench_ph_LDADD = $(top_srcdir)/src/.libs/ph.o
+bench_ph_LDADD = $(top_builddir)/src/.libs/ph.o